1. Field of the Invention
The present invention relates to a method for analyzing at least one characteristic of an elastomeric material included in a tire, wherein a NMR measuring is applied to a tread block of the tire by means of a NMR measuring system including a NMR sensor.
Moreover, the present invention also relates to an apparatus for carrying out the method mentioned above.
2. Description of the Related Art
Accordingly the present invention makes use of an analyser based on NMR (Nuclear Magnetic Resonance) measurements.
Quality control at the end of the manufacturing process is of great importance in the rubber industry, in particular in the manufacturing of tires.
Apart from non-destructive methods for quality check of tires uniformity and integrity, most of the methods commonly used for quality control of elastomeric material included in tires, are destructive and require test samples to be taken out from the tire.
Efforts in order to find non-destructive methods have been already made in the art.
For example, NMR (Nuclear Magnetic Resonance) measurements are known in the material research in order to analyze the material characteristics. To this aim, by means of a NMR measuring system a NMR signal is generated in an area adjacent the NMR sensor surface, which signal is measured in order to characterize the properties of the materials in the vicinity of the surface adjacent to the NMR sensor. NMR measuring systems of this kind are commercially distributed, for example, by BRUKER GmbH, 76287 Rheinstetten, Germany.
The material to be examined is magnetized so the spin of the atoms will be adjusted according to the magnetic field lines. The adjustment of the spin of atoms is disturbed by an additionally applied electromagnetic signal (disturbing signal). After switching off the additional electromagnetic field, the spin of the atoms will go back to their alignment of the magnetic field lines. At the moment of going back to their originally orientation they will send out a feedback signal which is characteristic for the environment or for the material characteristics. Usually, the disturbing signal is formed by a plurality of pulse signals.
A general description relative to NMR measuring method may be found, for example, in “Nuclear Magnetic Resonance” (2001), Vol. 30, pg. 453-476.
United States Patent Application US 2002/0084783 discloses an apparatus for examining flat goods of polymeric material having reinforcement structures embedded therein, said apparatus being provided with a number of NMR sensor probes on a measuring surface of an examination body for nuclear magnetic resonance imaging analysis of the flat goods.
A “Newsletter” issued on 1 Mar., 2005 by “Zentrum Für Magnetische Resonanz E. V.” discloses the use of NMR sensors to control the quality, by non-destructive measurements, not only of test samples, but also of production intermediates and final products, in rubber industry, in particular in tire production.
For providing such NMR measurements in the tire field, the positioning of the NMR sensor must be as accurate as possible. Therefore, usually, the NMR measurements are manually performed so as to obtain repeatable and reliable measurements.
However, said manually performing measurements besides being time consuming, do not allow to analyze a high number of samples (i.e. tires) and, consequently, are not advantageously applicable on an industrial scale.